Am Thu, 6 Sep 2018 22:31:45 +0200
schrieb Olaf Hering <olaf@aepfle.de>:

> IF cpu0_hotpluggable is broken, then only "if (!cpu) return;" can help.

Another option is to do cpu_online() twice to check if device_offline did anything.
Not sure if the compiler would fold the two checks into a single check.

Olaf